One-piece trailing arm section

ABSTRACT

A trailing arm suspension is formed as a one-piece stamped body having a central web and two laterally spaced side walls. A wrap is to be secured to an axle and received in a recess between the walls. The integrated wrap has radially outwardly extending ledges which are welded to the walls, and which provide support surfaces along the axle axis. In further features, closing plates are mounted to the spaced side walls.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a trailing arm suspension for securing an axle on a heavy vehicle.

[0002] Trailing arm suspensions are known, and have an recess to receive an axle and may have an intermediate surrounding sleeve. The sleeve is mounted within the recess, and then secured to the axle. Typically, trailing arm suspensions have utilized at least two parts which must be welded together to form the trailing arm. Moreover, the sleeves which have been utilized have typically been cylindrical reinforcement sleeves. Thus, the weld between the sleeves and the trailing arm suspension has typically been a weld along the partial circumference of the recess. It would be desirable to provide a simplified trailing arm suspension. Further, it would be desirable to provide a connection between the trailing arm and the sleeve which is reliably strong.

SUMMARY OF THE INVENTION

[0003] In the disclosed embodiment of this invention, a trailing arm suspension is formed of a one-piece stamping which is folded into a desired shape. This one-piece stamping has a recess which extends over approximately 270° to receive a wrap assembly. The wrap assembly includes ledges which extend radially outwardly of the portion of the wrap assembly secured to the axle. These ledges provide weld locations for connection of the arm to the wrap, such that there is structure on the wrap supporting the arm in a direction generally along the axis of the axle.

[0004] In preferred embodiments of this invention, closing plates as well as a pivot bush are also secured to the one-piece body.

[0005] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is a perspective view of an inventive trailing arm suspension.

[0007]FIG. 2 is a partially exploded view of the FIG. 1 suspension.

[0008]FIG. 3 is an exploded view of a portion of the FIG. 1 suspension.

[0009]FIG. 4 is a cross-sectional view showing the arrangement of certain parts in the inventive suspension.

[0010]FIG. 5A shows one wrap embodiment.

[0011]FIG. 5B shows a feature of the FIG. 5A wrap.

[0012]FIG. 6 shows the connection of the wrap to the arm.

[0013]FIG. 7 shows an alternative connection of the wrap to the arm.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0014] A suspension 18 includes a pivot bush 19 which will pivotally attach the trailing arm suspension to a vehicle frame. A wrap assembly 20 surrounds an axle, and will be welded to the axle. The arm body 22 includes a recess 24 which is welded to ledges 26 extending radially outwardly of the wrap 20.

[0015] As shown in FIG. 2, the wrap 20 is initially formed separate of the recess 24. The outwardly extending ledges 26 are aligned within the recess 24, as will be better explained below.

[0016] As shown in FIG. 3, the arm body 22 is formed as a one-piece metal stamping. Side plates 32 and 34 extend downwardly from a top connecting control web 35. The pivot bush tube 19 is received in an opening near the front of the sides 32 and 34. A shock tube 36 extends through holes 38 in side walls 32 and 34.

[0017] Rear spaced side walls 40 extend rearwardly of the recess 24. A top closing plate 41 is secured to the walls 40 and a bottom closing plate 42 is also secured to the walls 40. A forward bottom closing plate 44 is secured to the walls 32 and 34.

[0018] As perhaps best shown in FIG. 2, the members 26 extend outwardly of the remainder of the wrap body. An axle is received within the wrap body 20, as explained above. The wrap body 20 would be welded to the axle, preferably via the puddle weld windows 200.

[0019] One wrap embodiment 20 is illustrated in FIG. 4 having inner periphery 50 which will receive the axle. The arm inner surface 54 is secured to a plurality of spaced castellations 52. The castellations 52 are welded to the inner surface 54 of the arm. This connection will allow the joint some compliance while still ensuring a durable joint.

[0020]FIG. 5A shows a distinct wrap embodiment having wrap halves 70 and 76. The ridges are formed by ledge halves 74 and 78 on the two wrap halves. A tongue 72 extends radially outwardly, and generally perpendicularly to the ridges 74 and 78. The wrap halves are shown secured to axle 200. Typically, a weld joint connects the wrap halves to the axle.

[0021] As can be seen in FIG. 5B, the tongue 72 fits snugly into the space formed by the inner wall 79 of the central web 35 and the inner surfaces 81 of the two side walls. In this fashion, the tongue 72 thus provides additional support. At least one edge of the tongue 72 is welded to the inner periphery of the arm.

[0022] One connection embodiment shown in FIG. 6 connects the arm to the sleeve by a ledge with surfaces 62 and 64 and receives the trailing arm 24. This provides space at 65 to receive a butt weld to secure the two together. As can be appreciated, the surface 62 provides support along the axis of movement of the axle for the arm body portion which forms the recess 24. As can be appreciated, there would be a second similar connecting surface spaced axially from this surface on the other end of the arm. Notably, as shown in FIG. 6, the trailing arm body portion 24 is axially outwardly of the surface 26. That is, the other portion 26 and the other part of the trailing arm 24 would be to the left of the FIG. 6 view.

[0023] An alternative connection embodiment is shown in FIG. 7. In this embodiment, the arm 100 fits onto the ledge 102. There is a recess 104 beneath the ledge body such that the ledge extends axially inwardly through an angled portion 106 to the portion 108 which receives the arm. This recess allows some flexibility in the connection. Again, a weld recess 110 is provided.

[0024] The preferred embodiments of the invention have been disclosed. However, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason the following claims should be studied to determine the true scope and content of this invention. 

1. A trailing arm suspension for securing an axle to a vehicle frame comprising: a trailing arm body having spaced side walls, and a pivot connection at one axial end, a recess formed at an intermediate portion along said arm; a wrap assembly to be welded to said walls, said wrap assembly having a bore to receive an axle, said wrap assembly having radially outwardly extending ledges, said walls of said arm being welded to said radially outwardly extending ledges.
 2. A trailing arm suspension as set forth in claim 1, wherein there are a pair of axially spaced ledges.
 3. A trailing arm suspension as set forth in claim 1, wherein said wrap is formed of two portions.
 4. A trailing arm suspension as set forth in claim 3, wherein one of two said wrap portions has an outwardly extending tongue formed to extend axially between said ledges.
 5. A trailing arm suspension as set forth in claim 4, wherein said tongue is welded to an inner peripheral surface of said arm.
 6. A trailing arm suspension as set forth in claim 5, wherein said tongue fills a space between said spaced side walls and a central web which connects said spaced side walls.
 7. A trailing arm suspension as set forth in claim 1, wherein said sleeve has circumferentially spaced castellation in said ledge.
 8. A trailing arm suspension as set forth in claim 1, wherein the connection between said walls and said ledge includes said ledge having a stepped surface including a first inner portion, and a second axially outwardly extending portion, and with said arm received abutting said inner portion, and radially outwardly of said outwardly extending portion.
 9. A trailing arm suspension as set forth in claim 8, wherein a space is provided radially between a lower portion of said wall and said outwardly extending portion, said space receiving a weld joint.
 10. A trailing arm suspension as set forth in claim 8, wherein said inner portion is formed by an angled portion extending from said outwardly spaced portion, with a recess being formed radially between said inner portion and a nominal outer peripheral surface of said sleeve.
 11. A trailing arm suspension as set forth in claim 1, wherein closing plates close open spaces between said walls of said arm body.
 12. A trailing arm suspension comprising: a body including a thin sheet of metal stamped to have a central web and two laterally spaced side walls, a recess formed in each of said laterally spaced side walls, and closing plates secured to at least one surface of said side walls positioned vertically spaced from said central web.
 13. A trailing arm suspension as set forth in claim 12, wherein said recess extends for approximately 270°.
 14. A trailing arm suspension as set forth in claim 13, wherein said recess is secured to ridges on an outer periphery of a sleeve which is to receive an axle.
 15. A trailing arm suspension as set forth in claim 12, wherein walls on one side of said recess are spaced and closing plates are secured to both upper and lower surfaces of said spaced walls, said wev found on an opposed side of said recesses and a closing plate is only formed on one of an upper and lower surface of said opposed side spaced walls. 